In some communication environments, communication service must always be available to a customer. For example, during times of war, the military must always have access to telephony service so that military orders and objectives may be sent and received. Once the lines of communication fail, it is very difficult for commanding officers to implement strategies without having all the information available to them.
Therefore, there is a need for a communication service that provides certain users within a network with uninterrupted service. For these critical subscribers, dual-switch connectivity needs to be provided to guarantee that these subscribers will be able to initiate and receive communications even when the subtending central office or access line is unable to process calls. These techniques should ensure that the subscriber's normal features and functions are not degraded or lost. (In this disclosure, “communications” refers to the sending or receiving of any type of media or information, such as, for example, audio, video, data, or fax. Accordingly, aspects of the disclosed technology may relate to ordinary telephony as well as to more sophisticated communications services. All of these types of services are meant to be included in the term “communications”. However, for simplicity, this disclosure, in large part, is written in terms of ordinary telephony.)
Additionally, there is a need for the network to automatically sense and reroute incoming/outgoing communications during outages at the subtending central office, link or access line, and to continue to provide class of service and features authorized to the subscriber's assigned telephone number. There is also a need for the network to automatically reset to a default configuration when the subtending central office, link or access line has been restored.